I study the physiology of exercise and field energetics in vertebrates. These two are related, in as much as I am interested in the role of the circulatory system in the transport of oxygen in exercising animals. In doing so, I and my colleagues have established relationships between heart rate and rate of oxygen consumption in species from every Class of vertebrate except amphibians.  By using implantable data loggers, we are currently using heart rate to estimate field metabolic rate throughout the annual cycle in a number of species of aquatic birds and mammals. Thus we are able to determine the energy costs of various activities during the year including during the non-breeding period, when the location of the animals is often unknown. We have just started a field project investigating the behaviour, energetics and physiology of bar-headed geese migrating between India and China/Mongolia, which involves flying over the Himalayas. This is interesting not only because they fly at altitudes where the partial pressure of oxygen is 1/3 the sea level value, but also because they are possible vectors of avian influenza. We are also conducting a field/laboratory study on the energetic and visual constraints on foraging behaviour of great cormorants.

Portugal, S.J., Green, J.A. and Butler, P.J. 2007. Annual changes in body mass and resting metabolism in captive barnacle geese (Branta leucopsis): the importance of wing moult. J. exp. Biol. 210, 1391-1397.

Pelletier, D., Guillemette, M, Grandbois, J-M and Butler, P.J. 2007. It’s time to move: linking flight and foraging behaviour in a diving bird. Biol. Lett. 3, 357-359.

Halsey, L.G., Butler, P.J., Fahlman, A., Bost, C.-A., Woakes, A.J., Handrich, Y. 2008. Modeling the marine resources consumed in raising a king penguin chick: an energetics approach. Physiol. Biochem. Zool. 81, 856-867.

Rey, B., Halsey, L.G., Dolmazon, V., Rouanet, J-L., Roussel, D., Handrich, Y., Butler, P.J. and Duchamp, C. 2008. Long-term fasting decreases mitochondrial avian UCP-mediated oxygen consumption in hypometabolic king penguins. Am. J. Physiol 295, R92-R100.

White, C.R., Terblanche, J.S., Kabat, A.P., Blackburn, T.M., Chown, S.L. and Butler, P.J. 2008. Allometric scaling of maximum metabolic rate: the influence of temperature. Func. Ecol. 22, 616-623

Pelletier, D., Guillemette, M., Grandbois, J-M. and Butler, P.J. 2008. To fly or not to fly: high flight costs in a large sea duck do not imply an expensive lifestyle. Proc. Roy. Soc. 275, 2117-2124.

Kabat, A.P., Blackburn, T.M., McKechnie, A.E. and Butler, P.J. 2008. Phylogenetic analysis of the allometric scaling of therapeutic regimes for birds. J. Zool. 275, 359-367.